The scope of childhood cancer in South Africa: A response to ‘Childhood cancers in a section of the South African private health sector – Analysis of medicines claims data’

Childhood cancer is an under resourced medical field that is emerging as a great healthcare concern in low- and middle-income countries such as South Africa. Therefore, reporting data in this field that may inform policymakers should be representative of the subject matter. This article aims to discuss why medicines claims as an indicator for incidence, as per an article published in 2020, is not representative of childhood malignancies in the South African setting. Literature to support the commentary were sourced using Pubmed, Google scholar, and data presented by members of the South African Children’s Cancer Study Group (SACCSG). Private medical aid coverage in South Africa between 2002 and 2018 varied between 15.5% and 18.2%. Of these, 9.5% were children under 18 years and 3.5% were under the age of six. Only 13.5% of children were treated in private paediatric oncology units during 2015. The limitations in the study were the variable medical aid coverage, the disproportionate age representation, and lack of reliable indicators for measurement and calculation of incidence. Utilising one medicines claims data base to evaluate the incidence of childhood cancer in South Africa is not representative and cannot inform policy. Contribution This article highlights the importance of accurate registration of childhood cancer diagnoses, especially when data and conclusions based on these results inform policy. The study highlights the limitations of extrapolating general conclusions based on data representing only a small sector of the childhood cancer landscape in South Africa.


Introduction
The incidence of childhood malignancies is increasing globally (Gupta et al. 2014). This is because of the improved awareness, diagnostic capabilities, and the increased quality of reporting of incidences (Gupta et al. 2014). Nonetheless, independent from the resource setting, distinguishing the non-specific early symptoms of childhood cancer from more common childhood diseases remains challenging even with the increased quality of medical systems (Stones 2010:314).
The lack of high-quality data has been cited as a reason for inaccurate reporting of the incidence of childhood cancers in sub-Saharan Africa and South Africa (Erdmann et al. 2015(Erdmann et al. :2628Magrath et al. 2013:104). It is not only because of the absence of registries, but that registers are dependent on healthcare workers and administrators to include data into the registries (Stefan et al. 2015:939). These registries have quality controls to ensure accurate reporting. This includes screening for double registrations and the use of different identifiers for the same patient (Stefan et al. 2015:939). Other sources to describe possible incidences in childhood malignancies are available, but lack the same standards necessary for representative information.
The medicines claims of the South African private health sector was analysed by Otoo et al. (2020 based on a database of a single South African Pharmaceutical Benefit Management (PBM) company. The market share of the PBM was not included but covered 1.8 million beneficiaries. During a 10-year period between 2008 and 2017, only 173 new cases of childhood cancers were identified in the database. The article thus concluded that the incidence of childhood cancer in a part of the private medical sector was decreasing.
Childhood cancer is an under resourced medical field that is emerging as a great healthcare concern in low-and middle-income countries such as South Africa. Therefore, reporting data in this field that may inform policymakers should be representative of the subject matter. This article aims to discuss why medicines claims as an indicator for incidence, as per an article published in 2020, is not representative of childhood malignancies in the South African setting. Literature to support the commentary were sourced using Pubmed, Google scholar, and data presented by members of the South African Children's Cancer Study Group (SACCSG). Private medical aid coverage in South Africa between 2002 and 2018 varied between 15.5% and 18.2%. Of these, 9.5% were children under 18 years and 3.5% were under the age of six. Only 13.5% of children were treated in private paediatric oncology units during 2015. The limitations in the study were the variable medical aid coverage, the disproportionate age representation, and lack of reliable indicators for measurement and calculation of incidence. Utilising one medicines claims data base to evaluate the incidence of childhood cancer in South Africa is not representative and cannot inform policy.
Contribution: This article highlights the importance of accurate registration of childhood cancer diagnoses, especially when data and conclusions based on these results inform policy. The study highlights the limitations of extrapolating general conclusions based on data representing only a small sector of the childhood cancer landscape in South Africa.
Keywords: childhood cancer; medical policy; medical aid claims; incidence; oncology.

The scope of childhood cancer in South Africa: A response to 'Childhood cancers in a section of the South African private health sector -Analysis of medicines claims data'
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As stated in the article, data are used to develop cancer control strategies, evaluate changes in disease burden, and implement policies (Otoo et al. 2020. Most importantly, data informs the policy. Therefore, an accurate representation and conclusions based on data are of great importance.

Aim
The aim of this commentary is to discuss why medicines claims as an indicator for incidence is not representative of childhood malignancies regardless of the sector of the population in the South African setting.

Comments Limitations in the Otoo et al. (2020) study
The original study partially acknowledged the limitations that the study was based on a single PBM database analysis, that there are discrepancies in incidences and the diverse way in which medical accounts are paid, but still maintained that the data could be used for policy purposes (Otoo et al. 2020. In addition, two important limitations of the study are that it does not indicate if the patients were newly diagnosed during the study period and the 'medicine claims' on which data extraction was based, were never defined.

Heterogeneous medical systems, sector of management and remuneration
The South African medical system is heterogeneous comprising both the private and public sector (Coovadia et al. 2009:817). In the public sector, children under the age 6 year are treated for free. The remuneration in the public sector is based on the income per household, but also manages patients with private medical funding (Coovadia et al. 2009:817). The private sector is remunerated by both private medical funding and non-medical aid payments (Coovadia et al. 2009:817  Considering the representation of the database (less than 50% of medical aid claims) used in the study, the conclusions are only applicable to less than 10% of the childhood malignancies in South Africa.
Beneficiaries do change private medical aid funding for various reasons (Omotoso & Koch 2017:575; Van den Heever 2012). The implication is that patient (encrypted) numbers may change. Although not the only data collected, this was the primary indicator used in their study (Otoo et al. 2020. Cancer treatment is done over years, which limits the age of a patients as a reliable identifier. Referrals between private oncology units do occur and families relocate for several reasons. Referrals may take place because of the need for specialised expertise such as bone marrow transplantation. Utilising the prescriber's postal code would further contribute a confounder to the study. In a large dataset, these confounders may have a limited impact on the results, but in the Otoo et al. (2020) study, confounders may contribute to multiple representation of the same patient in the dataset. Thus, an overestimation of the incidence.

Distribution of paediatric oncology units
During 2002-2017, private POUs were only located in Bloemfontein, Cape Town, Durban, Johannesburg, and Pretoria (see Figure 2). This was reflected in the provincial distribution between Freestate, Gauteng, KwaZulu-Natal and the Western Cape in the Otoo et al. (2020)

The age representation
In the Otoo et al. study, the adolescent population represents a disproportionately high percentage compared to international statistics (Steliarova-Foucher et al. 2017). Two possible reasons for this are: (1) adolescents in the private sector (and public sector) are treated by adult oncologists, of whom there are more in the private sector.
(2) The greatest percentage of nonadolescent children are treated in the public sector. The very fact of inverse representation indicates a non-representative sample in their data base.

Increasing populations
The population of South Africa, and thus the child population, has increased in the period described in Otoo

Other funding options
Novel chemotherapeutic options are expensive and not always covered by medical aid funds (Meropal & Schulman 2009:180). To be able to pay for these treatments, families deplete savings, sell property or start funding opportunities such as crowdfunding. The pharmaceutical industry provides medication through compassionate use and medical need programmes (Gerasimov et al. 2020;Moerdler et al. 2019). All of these do not reflect in medical aid payments.

Possible representative solutions
In South Africa, there are currently two cancer registries that include children and adolescents: The South African Children's Tumour Registry (SACTR) and the South African National Cancer Registry (SA-NCR). By combining the data from PBMs, SACTR and SA-NCR, while observing the required quality controls for registries data, a truly representative population-based registry can be established.
If PBMs are to be used as a source of data, the research question should be in line with the data possibilities and limitations such as the resources needed during the treatment of children with specific cancers or observing resource trends.
Furthermore, these studies should be conducted per childhood cancer diagnosis as the treatment between malignancies differ vastly.
https://www.hsag.co.za Open Access Otoo et al. (2020) have presented a very small segment of the paediatric oncology landscape of South Africa while considering the possibility of using the data for policy decisions. The study does not evaluate a representative sample of paediatric oncology care, neither does it recognise the reality of the inequitable paediatric oncology services that exist in South Africa and how it is funded. Therefore, basing policy decisions with far-reaching implications on this study would be flawed.